What kind of duct do I need for range hood?

The minimum duct size for a range hood is 4”. This duct size is appropriate for low-CFM hoods from big box stores. Most range hoods will require between 6” and 8” duct, while more powerful outdoor or professional range hoods may require 10” duct or larger.

Can I use flexible duct for range hood?

Specifically, don’t use a flexible duct when you install the hood. It is not efficient in filtering out the soot in the kitchen. This material might even trap the substances because it does not have a smooth interior. Choose a rigid duct for your range hood so you will not go wrong.

What size is range hood ducting?

The minimum allowed duct size is 3¼” x 10″, or 6″ diameter for round ducts. Never use a plastic duct or one that is smaller than the size specified for the hood as this will directly affect the hood’s performance. High performance hoods require larger, up to 10″ diameter ducts.

Can you vent range hood with PVC?

PVC pipe is not allowed to be used for a range hood unless when the case falls within the exceptions stipulated by the International Residential Code, which permits the use of schedule 40 PVC pipe. Even in these cases, there are many rules and regulations to adhere to regarding the duct’s installation and location.

Can I use rectangular duct for range hood?

Most hood exhaust systems will work more efficiently with a round duct system, however if you are running an older system then a rectangular system may be required. However in the end most kitchen spaces will benefit greatly from going with the round ducts.

Can I use 5 inch duct for range hood?

If you have a range hood with a CFM of 0-400, you will need a minimum duct size of 4”. If your hood is between 401 and 600 CFM, you need a minimum duct size of 6”. If your hood is between 601 and 900 CFM, you need a minimum duct size of 7”.

Does kitchen exhaust duct need to be insulated?

You can insulate your vent hood duct, but it’s not required. Insulating your vent hood duct will keep the noise down and keep your greasy kitchen air from escaping into your joists and attic.

Is 400 cfm enough for a gas range?

To power your range hood, you need at least 100 CFM for every 10,000 BTUs of your stovetop. For example, a 100,000 BTU stove needs at least a 1000 CFM range hood. For electric stoves, multiply the stove width by 10. So, for a 42” electric stove you want a range hood with at least 420 CFM.

Do range hoods need to be vented outside?

Range hoods do not have to be vented to the outside. You can purchase hoods without ductwork called ductless hoods. But, ducted range hoods are almost always preferred over ductless hoods.

How far can you duct a range hood?

How far can you vent a range hood? Your range hood duct should not exceed 30′ for a straight run, 25′ for a run with one elbow, and 20′ for a run with two elbows. The shorter the duct, the better. If your ductwork is too long, your kitchen air may not reach the outside.

Can semi rigid duct be used for range hood?

You can choose from a flexible duct, semi-rigid duct, or rigid duct. Flexible ducts are not appropriate for kitchen hoods.

How many CFM is a 4 inch duct?

Reviewing the chart, a 4” pipe will convey 395 CFM at 4500 FPM. This means that a 4” pick-up on a machine will use 395 CFM from the filtering system; or, if you know that a machine will require approximately 400 CFM to remove the waste, you should use a 4” pipe for that purpose.

How many CFM can a 8 duct handle?

8-inch rectangular CFM duct chart (from 4×8 to 36×8 duct sizes).
CFM Sizing Chart For Metal Round Ducts (50-2,000 CFM)

Duct Size (Inches) Metal Duct Airflow (CFM)
5 inches 50 CFM
6 inches 85 CFM
7 inches 125 CFM
8 inches 180 CFM

How many CFM can a 12 round duct handle?

Using the chart, you’ll see that for a 12” round flex duct, maximum CFM is 480 CFM or 500 CFM depending on the friction rate. Duct size for 115 CFM.

Does duct length affect CFM?

Texas A&M did a study on the effect of flex duct not pulled tight and the results are astounding. In my article on this research, I showed from their results that a 6″ duct moving 110 cfm when pulled tight will move only about 70 cfm with 4% linear (longitudinal) compression and about 40 cfm or less at 15% compression.

How many CFM does a 6 inch duct have?

“For example, most techs will tell you that a 6” duct will provide about 100 CFM.”

What size duct is needed for 1200 CFM?

10” diameter

The higher the cubic feet per minute, the larger the duct you’ll need. At 600 CFM, the minimum duct size is 6”. At 900 CFM, the minimum duct size is 8”. Finally, at 1200 CFM and above, consider a 10” diameter duct or larger.

How many CFM do I need for a 12×12 room?

One cfm per square foot of floor area is the average air quantity required for a room or entire building.

How do you calculate supply duct size?

To calculate the required equipment size, divide the HVAC load for the entire building by 12,000. One ton equals 12,000 BTUs, so if a house or office needs 24,000 BTUs, it will take a 2-ton HVAC unit. If you get an uneven number, such as 2.33 for a 28,000 BTU load capacity, round up to a 2.5-ton unit.